This invention relates, in general, to video display systems, and more particularly, to a video display address generator.
There are many video scan display systems available. These video systems are capable of displaying characters such as used in text material as well as images of scenes. Video display systems having means for displaying data characters as well as for modifying the video characteristics of the displayed characters are known in the art. Typically such systems have a fixed number of video modifications that can be made. Such modifications or enhancements usually deal with other than pel modifications. "Pel" refers to the particular horizontal and vertical screen resolution of the display system which is the smallest picture element on the screen that can be controlled by data in the memory. Many of these prior art systems although having various capabilities did not have all the features desirable in today's market incorporated into a practical system.
Accordingly, it is an object of the present invention to provide an improved video display address generator for a video display system.
Another object of the present invention is to provide a video display address generator which allows new hardware techniques to more efficiently implement functions of a complex display address generator.
A further object of the present invention is to provide a display address generator useful in generating addresses for horizontal and vertical scrolling, refreshing a memory, and supporting a large variety of virtual screen sizes.